Hydraulic oil well pump jack



Feb. 9, 1954 C, R, CRAFT 2,668,517 n HYDRAULIC OIL WELL. PUMP JACK Filed O01.. 25, 1951 5 Sheets-Sheet l 9 2 6g 01.0 56 l i?? 24! 23 Feb. 9 1954 3,V R, CRAFT 2,668,517

HYDRAULIC OIL WELL PUMP JACK Filed Oct. 23, 1951 5 SheetS-Sheet 2 y fw Feb. 9, 1954 c. R. CRAFT HYDRAULIC OIL WELL PUMP JACK 3 Sheets-Sheet 3 Filed Oct. 23, 1951 Writ a z mlvn m mv. II

rod and so actuating the pump.

3 upper end of the sleeve or piston rod 24 is enlarged or flanged at 29 to rest upon the screw cap 23 when in its lower position and the enlargement is apertured as at 3D to permit the polish rod 9 to extend therethrough.

3l is a polish rod clamp, tightly but releasably mounted on the polish rod and adapted to engage the upper end of the hollow piston rod or sleeve 24. 32 is a double box coupling threaded on the upper end of the polish rod 9.y which may be used to attach a separate tool to raise the polish rod independent of the movement of the piston.

34 is a bleeder outlet controlled .by a manual valve 35 communicating with the upper end of the jack cylinder above the plunger 26.' 36 is an intake pipe and 31 an exhaust pipe,.both communicating with the jack cylinder below the plunger. In view of the fact that the plunger is packed both in its relationship with the jack cylinder I9 and the central sleeve 20, and i9 and 20 are both welded to the base plate i8, if hydraulic iluid is forced in through the high pressure intake hydraulic iiuid line 36, and it cannot escape to the outlet hydraulic fluid line 31, the piston will go up, carrying with it the polish If, thereafter, the ilow is cut oif and the oil is allowed to escape through outlet 31, gravity will reverse the movement and cause the pump mechanism to descend.

38 is a housing on the chassis I5. It contains a motor which may be steam or electric or internal combustion as the case may be, diagrammatically indicated at 39. This motor drives a compressor diagrammatically indicated at 45. Iii is `an oil or hydraulic uid reservoir in the chassis 15 beneath the motor and pump housing. The pump may be a reciprocating pump, a centrifugal pump or any other desired type oi pump which will generate hydraulic pressure. 42 is a pipe leading from the pump to a T 43. 44 is a. pipe extending to the valve housing 45. In this housing is an intake valve 5t and the pipe 41 leads from the housing 45 to the high pressure intake line 36. ofcourse, connected by couplings in the usual manner.

48 is a pipe leading from the pipe 31 to the valve housing 49. The pipe 53 leads from the exhaust valve housing 4S to the pipe 5l which i leads to the reservoir fil. Between the T 43 and the return pipe 52 leading to reservoir 4| is a recirculating valve 53. rihis is an adjustable pressure control relief valve. It opens when a predetermined pressure has been reached to permit ilow from the pump to the reservoir bypassing the hydraulic jack cylinder.

Under ordinary circumstances, hydraulic iluid passes from the pump to the valve housing 45 past the open intake valve 46 into the cylinder and the piston rises. As the piston reaches the end of its stroke, the intake valve is closed and the pump pressure is bled off through the relief or recirculating valve 53. During the upward movement of the piston, the outlet valve 54 in the valve housing 49 is closed but, when the plunger or piston reaches the upper end of its excursion, this valve 55 opens and, since no oil is being fed to the piston, the oil escapes through the outlet valve to the reservoir. The resistance to iiow in the circuit including the outlet valve is suiiicient to prevent a free fall of the pump sucker rod and polish rod and to cushion the downward movement.

The pipes, T and valve housings are, f

This actuating of the valves is accomplished in the following manner: Extending laterally from the enlarged head 29 of the jack piston 22 is a valve operating rod bracket 55. This bracket supports a valve operating rod 55 which is free to reciprocate in a housing or valve operating guide 51. On this valve operating rod 56 are four control buttons 58, 59, 60 and 6l. The valve operating rod guide 51 is slotted adjacent the outlet valve housing 54 and the high pressure valve housing 45. A lever 62, extending from each of these valves, projects into the path of the buttons. As the piston moves up and down, these buttons contact these levers. The levers by any suitable snap action mechanism, of which many are standard in the valve held and the details of which are not here shown, will move each valve from open to closed position or vice versa as the jack operates.

Thus, with the intake valve open and the exhaust valve closed, the pump exerts a pressure to raise the piston or plunger. The plunger goes up, carrying with it the polish rod and also carrying with it the valve operating bracket and the valve operating rod. As the piston approaches the upper end of its stroke, the buttons 58 and 55 on the valve rod 56 close the intake.` valve and open the exhaust valve respectively. The pump goes right on pumping but now the discharge is bypassed and, since the exhaust valve 54 is open, the weight of the plunger and the string of sucker rods causes downward movement.- As the piston approaches the lower end of its excursion, the valves are again operated by the buttons 60 and El to close the exhaust and open the intake valve respectively. This happens a short distance before the end of the stroke so that the pump has time to build up pressure to cushion the downward movement and reverse it.

rThe longitudinal position of the valve rod 56 may be adjusted with respect to the longitudinal position of the plunger 22 by the threaded nuts, as indicated at 62. The buttons 58, 59, 60 and 6l may also be adjustably positioned on the valve stem 56, the particular means for locking the buttons on the valve being not here illustrated as they are conventional and form no part of the present invention. This adjustable arrangement makes it possible to change the length of stroke and also makes it possible to adjust the point at whichl during downward movement of the plunger, the cushioning effect is built up so that accurate, smooth operation of the oil well pump jack may be insured.

It will be realized that, Whereas I have described and illustrated an operative device, still many changes might be made in the size, shape, number, arrangement and disposition of the parts without departing materially from the spirit of my invention. I wish, therefore. that my showing be taken in a broad sense as diagrammatic and illustrative rather than limiting me to my precise showing.

I claim:

1. In an oil well pump uiack including a supporting base, a motor` cylinder on the base adapted to be positioned with its axis in alignment with the axis of the well, an annular piston in the cylinder, a sleeve within the cylinder concentric therewith and packing means between outer periphery of the piston and the inner periphery of the cylinder, and between the inner periphery of the piston and the outer periphery of `the sleeve, the bottom and top of the cylinder being apertured to permit the polish rod of a well pump to extend therethrough and project therefrom at both ends, means for supporting the polish rod on the piston above the upper end of the cylinder, hydraulic means for raising the piston.

2. In an oil well pump jack including a supporting base, a motor cylinder on the base adapted to be positioned with its axis in alignment with the axis of the well, anannular piston in the cylinder, a sleeve within the cylinder concentric therewith and packing means between the outer periphery of the piston and the inner periphery of the cylinder, and between the inner periphery of the piston and the outer periphery of the sleeve, the bottom and top of the cylinder being apertured to permit the polish rod of a well pump to extend therethrough and project therefrom at both ends, means for supporting the polish rod on the piston above the upper end of the cylinder, hydraulic means for raising the piston, means associated With the polish rod, above the cylinder for raising the rod independent of the piston.

3. In an oil well pump jack a supporting base, a motor jack cylinder mounted on the base whereby the axis of the cylinder may be aligned with the axis of a well, a hollow piston and hollow piston rod in the cylinder, a sleeve rigidly mounted in the cylinder within the piston and piston rod whereby there is a clear passage from top to bottom through the cylinder, a polish rod adapted to extend through the cylinder in such clear passage, means for supporting the polish rod on the piston, and separate means independent of the piston whereby the polish rod may be raised and lowered.

CHESTER R. CRAFT.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,548,559 Simpson Aug. 4, 1925 2,073,809 Salentine Mar. 16, 1937 2,201,739 Nicholson May 21, 1940 2,224,475 Evans Dec. 10, 1940 2,232,449 Habenicht Feb. 18, 1941 2,282,977 Mast May 12, 1942 2,346,026 Henricks Apr. 4, 1944 2,356,899 Stutter Aug. 29, 1944 2,504,218 Noll et al. Apr. 18, 1950 

